ZnSe as a surface passivation layer in quantum dot-sensitized solar cells plays an important role in preventing charge recombination and thus improves the power conversion efficiency(PCE).However, as a wide bandgap se...ZnSe as a surface passivation layer in quantum dot-sensitized solar cells plays an important role in preventing charge recombination and thus improves the power conversion efficiency(PCE).However, as a wide bandgap semiconductor, ZnSe cannot efficiently absorb and convert long-wavelength light.Doping transition metal ions into ZnSe semiconductors is an effective way to adjust the band gap, such as manganese ions.In this paper, it is found by the method of density functional theory calculation that the valence band of ZnSe moves upward with manganese ions doping, which leads to acceleration of charge separation, wider light absorption range, and enhancing light harvesting.Finally, by using ZnSe doped with manganese ions as the passivation layer, the TiO2/CdS/CdSe co-sensitized solar cell has a PCE of 6.12%, and the PCE of the solar cell increases by 9% compared with the undoped one(5.62%).展开更多
离子插层已成为提高δ-MnO_(2)作为水系锌离子电池正极材料的循环稳定性和倍率性能的有效策略,但在实践中离子的选择似乎相当随意.本工作选择Cu^(2+)插层δ-MnO_(2),因为Cu^(2+)和Zn^(2+)具有相似的直径,但Cu^(2+)的电负性(1.359)略高于...离子插层已成为提高δ-MnO_(2)作为水系锌离子电池正极材料的循环稳定性和倍率性能的有效策略,但在实践中离子的选择似乎相当随意.本工作选择Cu^(2+)插层δ-MnO_(2),因为Cu^(2+)和Zn^(2+)具有相似的直径,但Cu^(2+)的电负性(1.359)略高于Zn^(2+)(1.347).因此,Cu^(2+)与MnO_(2)晶格具有更强的相互作用,并且在Zn^(2+)和H+的嵌入/脱出循环期间可保持稳定.Cu掺杂的δ-MnO_(2)(CMO)生成了Cu–O键,其电化学性能得到了较大的改善.在2 A g^(-1)的高电流密度下循环600次后,CMO表现出出色的循环稳定性和100%的容量保持率,而原始δ-MnO_(2)的容量保持率仅为23%.当电流密度从0.2增加到2.0 A g^(-1)时,CMO还表现出优异的倍率性能,容量保持率为72%,远高于原始δ-MnO_(2)(32%).由于Cu^(2+)比Zn^(2+)具有更大的电负性,因此Cu–O键作为稳定的“结构之柱”提高了CMO的循环稳定性.Cu^(2+)掺杂还提高了CMO的电子电导率和离子电导率,降低了H+和Zn^(2+)在电极/电解质界面的电荷转移电阻,从而提高了其倍率性能.这项工作为使用插层策略提高电池电化学性能提供了新的见解.展开更多
如何安全、高效、简便地制备出具有优异电化学性能的超级电容器电极材料是当前人们十分关注的问题.这些特性通常与电极中的空位和杂质有关.为了研究空位对超级电容器阴极材料性能的影响,我们采用一步水热法制备了具有硫空位的CoNi2S4(r-...如何安全、高效、简便地制备出具有优异电化学性能的超级电容器电极材料是当前人们十分关注的问题.这些特性通常与电极中的空位和杂质有关.为了研究空位对超级电容器阴极材料性能的影响,我们采用一步水热法制备了具有硫空位的CoNi2S4(r-CoNi2S4)纳米片结构电极材料.利用拉曼光谱、X射线光电子能谱(XPS)等手段对硫空位的形成进行了表征.作为超级电容器的电极,r-CoNi2S4纳米片在电流密度为1 A g-1时具有1918.9 F g-1的高容量、优异的倍率性能(在电流密度为20 A g-1时,相对于1 A g-1的保持率为87.9%)和超常的循环稳定性.与原始的CoNi2S4纳米片电极(1 A g-1时容量为1226 F g-1)相比,r-CoNi2S4电极的性能显著提高.基于r-CoNi2S4正极和活性炭负极的不对称超级电容器具有较高的能量密度.通过点亮三种不同颜色的发光二极管(LED)灯,成功证明了该器件在实际应用中的可行性和巨大潜力.展开更多
离子交换技术被广泛用于调节过渡金属氧化物的成分,采用该技术制备的超级电容器电极材料,在保持其形貌的同时能增加其比容量.本文报道了一种新颖的电化学方法辅助制备复合Co_3O_4/NiCo_2O_4纳米材料.通过电化学离子交换,可以将Ni^(2+)...离子交换技术被广泛用于调节过渡金属氧化物的成分,采用该技术制备的超级电容器电极材料,在保持其形貌的同时能增加其比容量.本文报道了一种新颖的电化学方法辅助制备复合Co_3O_4/NiCo_2O_4纳米材料.通过电化学离子交换,可以将Ni^(2+)快速引入并部分替换Co_3O_4纳米材料中的Co^(2+),从而得到Co_3O_4和NiCo_2O_4的复合纳米材料.将其用作超级电容器正极材料,在5 mA cm^(-2)的电流密度下,其面电容达到了3.2 F cm^(-2),并展现出了良好的倍率性能及优异的循环稳定性.此外,两个串联的非对称器件(Co_3O_4/NiCo_2O_4//碳布)在充电3 min后可以将10个并联的绿色LED点亮大约6 min,展现出良好的实用性.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61376011,61704114,51402141,and 61604086)the Gansu Provincial Natural Science Foundation,China(Grant No.17JR5RA198)+2 种基金the Fundamental Research Funds for the Central Universities,China(Grant Nos.lzujbky-2018-119 and lzujbky-2018-ct08)the Fund from Shenzhen Science and Technology Innovation Committee,China(Grant No.JCYJ20170818155813437)the Key Areas Scientific and Technological Research Projects in Xinjiang Production and Construction Corps(Grant No.2018AB004)
文摘ZnSe as a surface passivation layer in quantum dot-sensitized solar cells plays an important role in preventing charge recombination and thus improves the power conversion efficiency(PCE).However, as a wide bandgap semiconductor, ZnSe cannot efficiently absorb and convert long-wavelength light.Doping transition metal ions into ZnSe semiconductors is an effective way to adjust the band gap, such as manganese ions.In this paper, it is found by the method of density functional theory calculation that the valence band of ZnSe moves upward with manganese ions doping, which leads to acceleration of charge separation, wider light absorption range, and enhancing light harvesting.Finally, by using ZnSe doped with manganese ions as the passivation layer, the TiO2/CdS/CdSe co-sensitized solar cell has a PCE of 6.12%, and the PCE of the solar cell increases by 9% compared with the undoped one(5.62%).
基金supported by Gansu Provincial Natural Science Foundation of China(17JR5RA198 and 21JR7RA470)the Cooperation Project of Gansu Academy of Sciences(2020HZ-2)+3 种基金the Fundamental Research Funds for the Central Universities(lzujbky-2018-119,lzujbky-2018-ct08,and lzujbky-2019-it23)the Key Areas Scientific and Technological Research Projects in Xinjiang Production and Construction Corps(2018AB004)Hubei University of Arts and Science(2020kypytd002)Xiangyang Science and Technology Research and Development(2020YL09)。
文摘离子插层已成为提高δ-MnO_(2)作为水系锌离子电池正极材料的循环稳定性和倍率性能的有效策略,但在实践中离子的选择似乎相当随意.本工作选择Cu^(2+)插层δ-MnO_(2),因为Cu^(2+)和Zn^(2+)具有相似的直径,但Cu^(2+)的电负性(1.359)略高于Zn^(2+)(1.347).因此,Cu^(2+)与MnO_(2)晶格具有更强的相互作用,并且在Zn^(2+)和H+的嵌入/脱出循环期间可保持稳定.Cu掺杂的δ-MnO_(2)(CMO)生成了Cu–O键,其电化学性能得到了较大的改善.在2 A g^(-1)的高电流密度下循环600次后,CMO表现出出色的循环稳定性和100%的容量保持率,而原始δ-MnO_(2)的容量保持率仅为23%.当电流密度从0.2增加到2.0 A g^(-1)时,CMO还表现出优异的倍率性能,容量保持率为72%,远高于原始δ-MnO_(2)(32%).由于Cu^(2+)比Zn^(2+)具有更大的电负性,因此Cu–O键作为稳定的“结构之柱”提高了CMO的循环稳定性.Cu^(2+)掺杂还提高了CMO的电子电导率和离子电导率,降低了H+和Zn^(2+)在电极/电解质界面的电荷转移电阻,从而提高了其倍率性能.这项工作为使用插层策略提高电池电化学性能提供了新的见解.
基金financially supported by the Scientific Research Start-up Funds of Hexi University(KYQD2022004)the 13th Innovation Program Science and Technology for college students of Hexi University(138)。
基金supported by the National Natural Science Foundation of China(61376011 and 51402141)Gansu Provincial Natural Science Foundation(17JR5RA198)+1 种基金the Fundamental Research Funds for the Central Universities(lzujbky-2018-119 and lzujbky-2018-ct08)Shenzhen Science and Technology Innovation Committee(JCYJ20170818155813437)。
文摘如何安全、高效、简便地制备出具有优异电化学性能的超级电容器电极材料是当前人们十分关注的问题.这些特性通常与电极中的空位和杂质有关.为了研究空位对超级电容器阴极材料性能的影响,我们采用一步水热法制备了具有硫空位的CoNi2S4(r-CoNi2S4)纳米片结构电极材料.利用拉曼光谱、X射线光电子能谱(XPS)等手段对硫空位的形成进行了表征.作为超级电容器的电极,r-CoNi2S4纳米片在电流密度为1 A g-1时具有1918.9 F g-1的高容量、优异的倍率性能(在电流密度为20 A g-1时,相对于1 A g-1的保持率为87.9%)和超常的循环稳定性.与原始的CoNi2S4纳米片电极(1 A g-1时容量为1226 F g-1)相比,r-CoNi2S4电极的性能显著提高.基于r-CoNi2S4正极和活性炭负极的不对称超级电容器具有较高的能量密度.通过点亮三种不同颜色的发光二极管(LED)灯,成功证明了该器件在实际应用中的可行性和巨大潜力.
基金financially supported by the National Natural Science Foundation of China (61376011, 51402141 and 61604086)Gansu Provincial Natural Science Foundation (17JR5RA198)+2 种基金the Fundamental Research Funds for the Central Universities (LZUJBKY-2018-119 and LZUJBKY-2018-CT08)Shenzhen Science and Technology Innovation Committee (JCYJ20170818155813437)the Key Areas Scientific and Technological Research Projects in Xinjiang Production and Construction Corps (2018AB004)
基金supported by the National Natural Science Foundation of China (61376011)Gansu Provincial Natural Science Foundation of China (17JR5RA198)the Fundamental Research Funds for the Central Universities (lzujbky-2017-k21)
文摘离子交换技术被广泛用于调节过渡金属氧化物的成分,采用该技术制备的超级电容器电极材料,在保持其形貌的同时能增加其比容量.本文报道了一种新颖的电化学方法辅助制备复合Co_3O_4/NiCo_2O_4纳米材料.通过电化学离子交换,可以将Ni^(2+)快速引入并部分替换Co_3O_4纳米材料中的Co^(2+),从而得到Co_3O_4和NiCo_2O_4的复合纳米材料.将其用作超级电容器正极材料,在5 mA cm^(-2)的电流密度下,其面电容达到了3.2 F cm^(-2),并展现出了良好的倍率性能及优异的循环稳定性.此外,两个串联的非对称器件(Co_3O_4/NiCo_2O_4//碳布)在充电3 min后可以将10个并联的绿色LED点亮大约6 min,展现出良好的实用性.